In Elysium, Neill Blomkamp’s shrewdly revved-up and exciting dystopian thriller, Matt Damon sports a shaved head, which gives him a spooky ghost-face vibe, and his character, Max, spends most of the movie with a spidery black-metal exoskeleton implanted in his skull and spine. The surgically attached machinery serves several functions at once. It’s there to make Max strong — a boost he critically needs, since he’s been exposed to a dose of radiation that will leave him dead in just five days. It also allows him to download the contents of someone else’s brain. But the most important purpose served by that added hardware may be visual and symbolic: It transforms Max into a hulkingly damaged yet superheroic man-machine — a variation on the title character of RoboCop. And it has the unmistakable look of a cross that he’s been nailed to. Max isn’t just fighting to save himself or his fellow earthlings. He’s a guy who’s been souped up into a postapocalyptic action-movie Christ.

Elysium confirms the talent — for razory mayhem and shocking satire, for the crazed spectacle of future decay — that Blomkamp showcased in his amazing first feature, District 9 (2009). I’ve never forgotten that film’s images of gargantuan alien spaceships hovering in the air, or of droid wars as bloody and frenzied as a heavy-metal version of the Crusades. In Elysium, Blomkamp comes up with sci-fi conceits that sear themselves into your imagination. The film is set in 2154, and much of it takes place in a crumbling shantytown Los Angeles that suggests the concrete ghettos of Rio–meet–Blade Runner with the sun up and the lights turned off. Earth has become a great big slovenly police state, with citizens kept in check by clanging robot officers programmed to presume that you’re guilty. Max, a former car thief who now works on an assembly line (that’s where he gets zapped with radiation), is hauled before his parole officer, who turns out to be an old carnival mannequin that speaks like a voicemail menu and says things like ”Stop talking!”

Suspended above this hellhole society is a twirling, man-made satellite called Elysium, where the elite live. From a distance (it can be glimpsed in the noon sky), Elysium looks like the steering wheel of a ’60s Chrysler. Up close, we can see that the vast metal rim contains a sprawling prefab suburban paradise — acres and acres of pristine lawns and McMansions. The people who live there have all they want, yet Blomkamp’s sly joke is that even the world that everyone on Earth covets is a paper-thin and almost virtual place.

The key advantage of living on Elysium is that each home is equipped with a healing chamber that will cure everything from flesh wounds to cancer in five seconds. That’s why Max, joining forces with his old underworld cronies, will do anything to get there: It’s the only way his irradiated body can survive. Elysium takes off from a pure existential thriller situation (which it borrows from the great 1950 film noir D.O.A.), and it’s been shot in an incredibly effective mode of raggedy, quick-cut anxiety. Yet apart from that health care allegory (and the 1 percent–versus–99 percent theme it emerges from), the plot is fairly basic. I wish that the film had more of the tasty futuristic detail promised by that dummy parole officer. I also wish that Blomkamp took us deeper into the world of Elysium. Max has to outwit the fascist politician who’s plotting to take over (she’s played by Jodie Foster with angry clipped diction and not a lot more). But once he’s up there, Elysium turns into a virtuoso gun battle that might be taking place almost anywhere. What makes it matter is Damon, who has kicked ass before, but never with this kind of underlying brotherhood-of-man melancholy. B+